Wednesday, 2 March 2016

Biodiversity and the Beaver

I had an excellent opportunity last weekend to join a group of ecologists visiting the Devon Beaver Project, a trial study looking into how Eurasian Beavers (Castor fiber) adapt their surroundings, creating vital wetland habitat.

Beaver lodge and pool - the enclosure is about 2.8ha in total

Led by Mark Elliott of Devon Wildlife Trust, this fascinating project has now been running for 5 years. Beaver pools and dams provide excellent ecosystem services; holding the excess water, allowing gradual release back into rivers and streams after extreme flooding events (it turns out they might be even more effective landscape managers than us costly humans).

One of several Beaver dams - this one extends for over 20m

Their forte is creating a series of staggered pools, interconnected by small canals so that they can ferry woody materials around. They carry out all their own maintenance and repairs, needing absolutely no input from us.

Horizon pool (something I've always fancied in my garden)

These fluffy aqua-engineers have been gone from our landscapes over 400 years, hunted to extinction for their meat, fur and some weird medicinal value of their glands. Beavers are a 'keystone species', meaning their presence is important for the structure and function of a particular habitat. Remove the keystone and the habitat changes so drastically that the whole ecosystem on that site collapses.
   Beavers are nocturnal, so we didn't get a chance to see them in person, but the field signs of these massive rodents are pretty unmistakable...

Is that some Beaver hedge-laying? Tom Simpson himself would be impressed

Mark explained to us that many of these partially felled trees will continue to grow, with the fresh coppice regrowth creating Beaver 'salad bowls', on which they feed.


Not a T-Rex, but the Right hind footprint of Beaver, Europe's biggest rodent

Data are being meticulously gathered with the help of the University of Exeter. Water monitoring stations collect vital information on changes in flow and water quality on the site, all of which are improving for the better.




Of course, the thing us ecologists noticed the most after stepping rather gingerly into the site, is how Beavers create incredibly stunning, biodiverse and lush habitat! 


The act of opening up the dense scrub, allowing light to reach the network of pools and canals has resulted in a true habitat mosaic - all the work of just two adult Beavers.
   Increased amounts of frogspawn indicate a benefit to the amphibian populations...


The wet wood is no doubt a haven for aquatic invertebrates, hidden away in the cracks and crevices of the dams. Certainly the can fungi benefit from all of this fallen deadwood...

Scarlet Elf Cup (Sarcoscypha coccinea)

Blushing Bracket (Daedaleopsis confragosa)

Miniature water gardens contain many plant species, a few of which were not only new to me...

Beaver burrow

Young basal leaves of Marsh Ragwort (Senecio aquaticus)  - identified by Mark Elliott

Water Forget-me-not (Myosotis scorpioides), Water Mint (Mentha aquatica) and some type of Crowfoot

...which turned out to be Round-leaved Crowfoot (Ranunculus omiophyllus) - identified by Dave Green

Bog Pimpernel (Anagallis tenella) - identified by Mark Elliott

Lesser Spearwort (Ranunculus flammula) - identified by Mark Elliott

I can only imagine how spring and summer will bring even more burgeoning wildlife to this site. 
Thanks to Mark, Penny, Dave and David for letting me tag along, it really was a privilege. 

Find out more about the scientific benefits of Devon's Beavers in this report, and the positive effects on communities in the below video.